• Title, Summary, Keyword: Hybrid structures

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HYBRID LIGHTWEIGHT STRUCTURES -On Recent Projects aimed at Holistic Design

  • Saitoh, Masao
    • Proceeding of KASS Symposium
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    • pp.52-66
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    • 2005
  • Tension and Membrane have the potential to enable the realization of lightweight structures that have the attractive features of structures efficiency and aesthetical expression. Compared with pure (thorough-bred) tension structures such as cable net, air dome and tensegrity, so called hybrid tension structures such as beam string, tensegric system and other mixed structures have Potential still to be realized. After synnaruzubg the simple definition of tensegric structure, some holistic designs for hybrid tension structures completed recently in the author's practice are given.

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A Study on the Unit System of Hybrid System Using the Membrane and Tensegrity (막과 텐세그러티를 이용한 하이브리드 구조물의 단위 구조 제안)

  • Sur, Sam-Yeol;Ko, Kwang-Ung
    • Journal of the Korean Association for Spatial Structures
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    • v.5 no.2
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    • pp.81-87
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    • 2005
  • The Space structures may have large freedom in scale and form. And especially Hybrid structures are received much attention from the view points of their light weight and aesthetics. Hybrid systems are stable structures which are reticulated spatial structures composed of compressive straight members, struts and cables and Membranes. In this paper, The Hybrid Unit System are suggested using the Membrane and Cable elements based on the Tensegrity Unit system. Also, The Hybrid System of double-layered single curvature is presented. We analyze the force density method allowing form-finding for Tensegrity systems. And We analyze the shape analysis by the LARSH which is the program for nonlinear analysis.

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Equivalent modal damping ratios for non-classically damped hybrid steel concrete buildings with transitional storey

  • Sivandi-Pour, Abbas;Gerami, Mohsen;Khodayarnezhad, Daryush
    • Structural Engineering and Mechanics
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    • v.50 no.3
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    • pp.383-401
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    • 2014
  • Over the past years, hybrid building systems, consisting of reinforced concrete frames in bottom and steel frames in top are used as a cost-effective alternative to traditional structural steel or reinforced concrete constructions. Dynamic analysis of hybrid structures is usually a complex procedure due to various dynamic characteristics of each part, i.e. stiffness, mass and especially damping. In hybrid structures, one or more transitional stories with composite sections are used for better transition of lateral and gravity forces. The effect of transitional storey has been considered in no one of the studies in the field of hybrid structures damping. In this study, a method has been proposed to determining the equivalent modal damping ratios for hybrid steel-concrete buildings with transitional storey. In the proposed method, hybrid buildings are considered to have three structural systems, reinforced concrete, composite steel and concrete (transitional storey) and steel system. In this method, hybrid buildings are substituted appropriately with 3-DOF system.

Seismic behavior of structures isolated with a hybrid system of rubber bearings

  • Chen, Bo-Jen;Tsai, C.S.;Chung, L.L.;Chiang, Tsu-Cheng
    • Structural Engineering and Mechanics
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    • v.22 no.6
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    • pp.761-783
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    • 2006
  • The enlargement of interest in base isolators as an earthquake-proof design strategy has dramatically accelerated experimental studies of elastomeric bearings worldwide. In this paper, a new base isolator concept that is a hybrid system of rubber bearings is proposed. Uniaxial, biaxial, and triaxial shaking table tests are also performed to study the seismic behavior of a 0.4-scale three-story isolated steel structure in the National Center for Research on Earthquake Engineering in Taiwan. Experimental results demonstrate that structures with a hybrid system of rubber bearings composed of stirruped rubber bearings and laminated rubber bearings can actually decrease the seismic responses of the superstructure. It has been proved through the shaking table tests that the proposed hybrid system of rubber bearings is a very promising tool to enhance the seismic resistance of structures. Moreover, it is demonstrated that the proposed analytical model in this paper can predict the mechanical behavior of the hybrid system of rubber bearings and seismic responses of the base-isolated structures.

Non-linear stability analysis of a hybrid barrel vault roof

  • Cai, Jianguo;Zhou, Ya;Xu, Yixiang;Feng, Jian
    • Steel and Composite Structures
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    • v.14 no.6
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    • pp.571-586
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    • 2013
  • This paper focuses on the buckling capacity of a hybrid grid shell. The eigenvalue buckling, geometrical non-linear elastic buckling and elasto-plastic buckling analyses of the hybrid structure were carried out. Then the influences of the shape and scale of imperfections on the elasto-plastic buckling loads were discussed. Also, the effects of different structural parameters, such as the rise-to-span ratio, beam section, area and pre-stress of cables and boundary conditions, on the failure load were investigated. Based on the comparison between elastic and elasto-plastic buckling loads, the effect of material non-linearity on the stability of the hybrid barrel vault is found significant. Furthermore, the stability of a hybrid barrel vault is sensitive to the anti-symmetrical distribution of loads. It is also shown that the structures are highly imperfection sensitive which can greatly reduce their failure loads. The results also show that the support conditions pose significant effect on the elasto-plastic buckling load of a perfect hybrid structure.

A Study on the Theory and Application for the Morphological Aspects of Hybrid Spatial Structures (대공간구조물의 형태결정에 관한 이론 및 응용에 관한 연구)

  • 이경수;이상주;유용주;한상을
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.272-279
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    • 1998
  • The purpose of this study is to show how to gain the morphology of the Hybrid Spatial Structures and to get the geometrical data such as node coordinates, member relationships and graphic images. To form spatial structures, we have developed morphological aspects of general spatial structures, programming process and techniques. Structural design has many processes. Especially, it is very important to consider the determination of structural configuration. Regular Hybrid Spatial Structures have complex configuration, so we need to make use of automated computer process to determine structural shape in Hybrid Spatial Structures. We have applied morphological aspects to double layer plate, single layer dome, double layer dome and tensegrity structure.

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Global seismic damage assessment of high-rise hybrid structures

  • Lu, Xilin;Huang, Zhihua;Zhou, Ying
    • Computers and Concrete
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    • v.8 no.3
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    • pp.311-325
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    • 2011
  • Nowadays, many engineers believe that hybrid structures with reinforced concrete central core walls and perimeter steel frames offer an economical method to develop the strength and stiffness required for seismic design. As a result, a variety of such structures have recently been applied in actual construction. However, the performance-based seismic design of such structures has not been investigated systematically. In the performance-based seismic design, quantifying the seismic damage of complete structures by damage indices is one of the fundamental issues. Four damage states and the final softening index at each state for high-rise hybrid structures are suggested firstly in this paper. Based on nonlinear dynamic analysis, the relation of the maximum inter-story drift, the main structural characteristics, and the final softening index is obtained. At the same time, the relation between the maximum inter-story drift and the maximum roof displacement over the height is also acquired. A double-variable index accounting for maximum deformation and cumulative energy is put forward based on the pushover analysis. Finally, a case study is conducted on a high-rise hybrid structure model tested on shaking table before to verify the suggested quantities of damage indices.

Evaluation of Static Stability of Hybrid Carbody Structures of Korean Tilting Train eXpress Including Degradation Effects of Composite Materials under Ground Environments (지상환경하에서 복합재료의 물성저하를 고려한 한국형 틸팅열차 하이브리드 차체 구조물의 정적안정성 평가)

  • Shin, Kwang-Bok;Hahn, Seong-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.6
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    • pp.807-815
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    • 2004
  • In order to evaluate the static stability of hybrid carbody structures of Korean Tilting Train eXpress(TTX) caused by degradation of composites under ground environments, T300/AD6005 graphite/epoxy composite specimens were exposed to accelerated environmental conditions including ultraviolet radiation, temperature and moisture fer 2000 hours. It was found that the stiffness and strength of composites after aging were lower than those of unexposed specimens, and decreased as the aging time increases. The values of the degraded properties were used in the static analysis to check the static stability of hybrid carbody structures caused by environmental degradation of composites. The results shown that the structural stability of hybrid carbody structures was affected by the degradation of composites after exposure to accelerated aging environments.

Operation Principle and Topology Structures of Axial Flux-Switching Hybrid Excitation Synchronous Machine

  • Liu, Xiping;Wang, Chen;Zheng, Aihua
    • Journal of international Conference on Electrical Machines and Systems
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    • v.1 no.3
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    • pp.312-319
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    • 2012
  • The operation principle of an axial flux-switching hybrid excitation synchronous machine (AFHESM) is analyzed and its topology structures are proposed in this paper. After some comprehensive analysis of the operation principle to axial flux electrical machine, flux-switching electrical machine and hybrid excitation electrical machine, the operation principle of AFHESM is given. Combined with some typical topological structures of hybrid excitation electrical machine, some possible topological structures are proposed and some comprehensive comparisons are carried out. The analysis results show that the stator-separated AFHESM has some advantages such as less AM turns, less impact on the demagnetization of PM, less magnetic flux-leakage and higher efficiency compared to other topologies.

A hybrid CSS and PSO algorithm for optimal design of structures

  • Kaveh, A.;Talatahari, S.
    • Structural Engineering and Mechanics
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    • v.42 no.6
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    • pp.783-797
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    • 2012
  • A new hybrid meta-heuristic optimization algorithm is presented for design of structures. The algorithm is based on the concepts of the charged system search (CSS) and the particle swarm optimization (PSO) algorithms. The CSS is inspired by the Coulomb and Gauss's laws of electrostatics in physics, the governing laws of motion from the Newtonian mechanics, and the PSO is based on the swarm intelligence and utilizes the information of the best fitness historically achieved by the particles (local best) and by the best among all the particles (global best). In the new hybrid algorithm, each agent is affected by local and global best positions stored in the charged memory considering the governing laws of electrical physics. Three different types of structures are optimized as the numerical examples with the new algorithm. Comparison of the results of the hybrid algorithm with those of other meta-heuristic algorithms proves the robustness of the new algorithm.